TBS Phase III Exam Questions and Answers 2026 | 150+ Marine Corps Fire Support, Defensive Operations & Combat Engineering Questions | FOCDPIG, TTLODAC, Machine Guns, FSCMs & Night Attacks | The Basic School (TBS)

This comprehensive TBS Phase III Exam study guide contains more than 150 exam-style questions and verified answers covering fire support planning, defensive operations, machine gun employment, combat engineering, obstacle integration, night attacks, movement to contact, engagement area development, and tactical planning concepts taught at The Basic School (TBS). Designed for Marine Corps officers, officer candidates, NROTC midshipmen, PLC candidates, OCC candidates, infantry leaders, weapons platoon commanders, and professional military education students, this resource provides a detailed review of the doctrinal principles, battlefield procedures, and tactical decision-making skills required for success during TBS Phase III evaluations and field exercises. The material reinforces core warfighting competencies while preparing students for both academic testing and practical leadership assessments. A major focus of the guide is fire support planning and coordination. Students will learn how to develop effective fire support plans using TTLODAC (Target, Trigger, Location, Observer, Delivery System, Attack Guidance, and Communications Net), establish fire support tasks and effects, and integrate long-range fires, close-in fires, and final protective fires into defensive and offensive operations. The material examines Fire Support Coordination Measures (FSCMs), including permissive measures such as Free Fire Areas (FFA), Fire Support Coordination Lines (FSCL), Battlefield Coordination Lines (BCL), and Coordinated Fire Lines (CFL), as well as restrictive measures including Restrictive Fire Areas (RFA), Restrictive Fire Lines (RFL), and No Fire Areas (NFA). These concepts are essential for synchronizing maneuver and fires while minimizing the risk of fratricide. The document provides extensive coverage of defensive operations planning and execution. Students will review defensive operations orders using the TDOOTS framework (Type and Method of Defense, Distribution of Forces, Occupation Method, Orientation, Tactical Control Measures, and Security), engagement criteria, target precedence, security plans, stand-to procedures, defense-in-depth concepts, and command post placement. Additional instruction covers engagement area development, target reference points (TRPs), fire plan sketches, sectors of fire, final protective lines (FPLs), principal directions of fire (PDFs), and machine gun employment within defensive schemes of maneuver. These topics emphasize how Marine leaders organize, coordinate, and defend battle positions against enemy attacks. Machine gun doctrine receives significant attention throughout the study guide. Students will master the Eight Principles of Machine Gun Employment (PICMDEEP): Pairs, Interlocking Fires, Coordination of Fires, Mutual Support, Defilade, Enfilade, Economy of Fires, and Protection. Additional topics include machine gun command relationships, direct support, general support, attachment relationships, displacement criteria (Method, Objective, Route, Time), offensive and defensive machine gun task statements, rates of fire for the M240B medium machine gun, and machine gun integration during consolidation and reorganization following objective seizure. These concepts are fundamental for maximizing firepower, battlefield coverage, and defensive effectiveness. Combat engineering and obstacle integration are explored in considerable depth. Students will review the four functional roles of engineers—Mobility, Countermobility, Survivability, and General Engineering—and their application in both offensive and defensive operations. The guide explains reinforcing obstacle employment principles through the FOCDPIG framework (Covered by Fire, Observed, Concealed, Employed in Depth, Protected, Integrated, and Non-Geometric), as well as obstacle reduction methods including mechanical, ballistic, and explosive techniques. Additional instruction covers tactical, protective, and supplementary wire obstacles, obstacle effects such as Turn, Fix, Disrupt, and Block, and the integration of obstacles with direct and indirect fires to shape enemy maneuver. Night operations and movement to contact planning are also addressed in detail. Students will study illuminated and unilluminated attacks, probable lines of deployment (PLDs), support-by-fire considerations, surprise, direction, and control—the "Trinity of the Night"—along with leader’s reconnaissance procedures, contact drills, rear guard operations, battle drills, rotation plans, link-up procedures, and movement-to-contact fundamentals. These concepts support tactical flexibility and effective combat leadership in limited visibility environments. The guide additionally includes instruction on CBRN contamination markers, engagement area development, commander's intent, principles of war, offensive operation types, task organization considerations, and engineer support requirements. Students will review battlefield indicators, contamination marking systems, avenues of approach analysis, kill zone development, obstacle emplacement, weapons system integration, and rehearsal procedures necessary for effective combat planning and execution. These topics reinforce the Marine Corps’ combined-arms approach to maneuver warfare and battlefield dominance. The content aligns closely with official Marine Corps doctrinal publications and professional military education references, including MCDP 1 Warfighting, MCWP 3-1 Offensive and Defensive Tactics, MCWP 3-15.1 Machine Guns and Machine Gun Gunnery, MCWP 3-17 Engineering Operations, Marine Corps Fire Support Doctrine, CBRN Defense guidance, and The Basic School Program of Instruction. These publications provide the doctrinal framework for tactical leadership, fire support planning, obstacle integration, machine gun employment, maneuver warfare, and combat engineering operations within the United States Marine Corps. This document is highly relevant for TBS students, Marine Corps officers, officer candidates, infantry officers, weapons platoon commanders, machine gun section leaders, combat engineers, fire support coordinators, CBRN officers, NROTC midshipmen, PLC candidates, OCC candidates, military academy students, and professional military education participants preparing for TBS Phase III examinations, officer qualification assessments, leadership evaluations, promotion boards, or advanced tactical training. It is particularly valuable for individuals seeking a comprehensive review of fire support planning, defensive operations, machine gun doctrine, obstacle integration, combat engineering, night attacks, and Marine Corps maneuver warfare principles. Keywords TBS Phase III, TBS Phase 3 exam questions, The Basic School, Marine Corps tactics, fire support planning, TTLODAC, fire support coordination measures, FSCM, FFA, FSCL, BCL, CFL, RFA, RFL, NFA, defensive operations, TDOOTS, engagement criteria, target precedence, target reference points, TRP, fire plan sketch, security plan, defense in depth, command post placement, machine gun employment, PICMDEEP, machine gun displacement, M240B rates of fire, final protective line, FPL, principal direction of fire, PDF, offensive machine gun tasking, defensive machine gun tasking, combat engineering, FOCDPIG, reinforcing obstacles, mobility operations, countermobility, survivability, general engineering, obstacle reduction, ballistic breaching, explosive breaching, mechanical breaching, tactical wire obstacles, protective wire obstacles, supplementary wire obstacles, turn fix disrupt block, CBRN markers, chemical contamination marker, biological contamination marker, radiological contamination marker, night attacks, PLD, movement to contact, engagement area development, commander’s intent, principles of war, Marine Corps doctrine, United States Marine Corps